Never heard of a DE-1/T. I don't think it is a Nikon reference.
The titanium DE-1 for the F2T is just called the DE-1 by Nikon.
The F2H also had a titanium DE-1 , but this DE-1 finder was silver-coated for maximum brightness, because the F2H had a fixed, semi-reflective (65% light transmission) pellicle mirror. Nikon also mention it as a DE-1
And, yes indeed, I'm searching for a titan DE-1